Calves benefit from mother’s post-colostrum milk

University of Guelph study identifies ‘bio-actives’ in days two to four of lactation

Farmers will have to examine how practical it is on their farms to provide several feedings of cow transition milk to their youngest calves. Photo:
iStock/Getty Images

Taking newborn calves completely off colostrum after one or two feedings may contribute to future health challenges, according to as-yet-unpublished research by the University of Guelph’s Department of Animal Physiology.

Instead, explained Associate Professor Dr. Michael Steele in the annual webinar series of the US-based Dairy Cattle Welfare Council (DCWC), it might be advisable to continue feeding what he referred to as “transition milk” containing a diminishing percentage of colostrum for six feedings or more, before moving to whole milk or milk replacer.

Why it matters: While implementing such a change would come with logistical and/or labour-management challenges on many dairy farms, the potential exists for healthier replacement animals.

Steele, who holds an Industrial Research Chair through the Natural Sciences and Engineering Research Council of Canada, told Farmtario his lab has been tasked by its dairy sector-based industry partners to improve the health outcomes for calves in early life. Recent surveys have pointed to as high as 10 per cent mortality among dairy herds in the first 10 days of life.

Among the topics touched on during the DCWC webinar – which had the title “Healthy Gut, Healthy Calf, Productive Future” – was a comparison of tube feeding versus bottle feeding of first and second-serving colostrum. Even though the two delivery methods transfer the milk to different locations in the gut (bottle feeding to the abomasum, tube feeding to the rumen), it now appears certain those early feedings of colostrum both end up quite quickly in the abomasum, and health outcomes are effectively equal either way.

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“I had thought that the bottle feeding would definitely be better, but we basically found no difference,” Steele said. “I guess the take-home is: If you have 20 calves born on the same day and you don’t have the labour on hand to bottle-feed each one, then it certainly makes sense to tube-feed.”

Recent work has also compared pasteurized versus non-pasteurized colostrum during those early feedings. Results indicate the beneficial antibodies and gut microflora that colostrum serves to transfer from mother to offspring are not harmed by pasteurization, while the heat treatment eliminates potentially harmful bacteria from the calving and post-calving environment. So his recommendation is to pasteurize.

Some of Steele’s other recent lab work involves a study into a calf’s transition from full colostrum to whole milk or milk replacer.

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The effectiveness of immediately post-freshening colostrum in transferring naturally-occurring immunoglobulins (or antibodies) is well-known. It’s also well-known that those immunoglobulins diminish after the first two milkings. Steele believes it was a common-sense approach to “try to mimic the natural biology of the cow” by taking a closer look at the molecular make-up of the milk in the hours and days after the antibodies are gone.

His lab’s analysis found what he called “a lot of bio-actives” in milk from the third, fourth, fifth and sixth milkings. These include oligosaccharides, insulin, and various proteins and DNA – all found at higher levels in the transition milk than in milk from the cow as it advances further into its lactation. These, Steele believes, have considerable potential for helping build a healthy gut microflora in the growing calf.

An experiment was set up to follow up early colostrum feeding in three different ways: straight to whole milk, continued colostrum, or a 50/50 blend of milk and colostrum. The as-yet-unpublished results indicate immunity to disease was effectively transferred from mother to offspring in all three feeding regimens, but gut health was compromised in the colostrum-to-whole-milk group.

Next steps, Steele noted, include singling out what appear to be the key “bio-actives” in transition milk, such as insulin or oligosaccharides, increasing their presence in a modified feeding regime, and hopefully determining their particular gut-health benefits.

Even now though, Steele said, “we can say that this transition milk is really potent in things that are going to make the calf healthy.”

Will it become common practice to feed transition milk through to the sixth, or even 10th milking? The researcher recognizes that, on most dairy farms, it needs to make sense from labour-management and financial standpoints.

But he encourages producers, if they aren’t already feeding beyond the first two colostrum milkings, to “think about creative ways to mix transition milk with their milk or milk replacer.” An example would be freezing a larger batch of transition milk in small proportions to be mixed in later.

“Plus,” he concluded, “if you’re basically dumping your transition milk right now instead of feeding it, that should be an easy one.”